Guidance

Monitoring emissions from back-up generators: RPS 353

Published 9 July 2025

Applies to England

© Crown copyright 2025

This publication is licensed under the terms of the Open Government Licence v3.0 except where otherwise stated. To view this licence, visit nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: psi@nationalarchives.gov.uk.

Where we have identified any third party copyright information you will need to obtain permission from the copyright holders concerned.

This publication is available at https://www.gov.uk/government/publications/monitoring-emissions-from-back-up-generators-rps-353/monitoring-emissions-from-back-up-generators-rps-353

Environment Agency regulatory position on when you do not need to monitor emissions from permitted medium combustion plant (MCP) that are used for back-up generation.

However, the Environment Agency will not normally take enforcement action against you if you do not comply with this legal requirement provided that:

  • your activity meet the description and circumstances set out in this RPS

  • you comply with the conditions set out in this RPS

  • your activity does not cause (and is not likely to cause) pollution of the environment or harm to human health

1. Activity this RPS applies to

This RPS applies to operation of one or more medium combustion plant that are permitted to operate for on-site back-up power generation and are tested for no more than 50 hours per year.

This RPS also applies to an installation with aggregated back-up capacity greater than 20 megawatt thermal (MWth) input that are regulated by the Environment Agency.

2. Circumstances in which this RPS applies

This RPS only applies when there is no existing permanent or safe means to monitor the emissions from your back-up generator.

3. Conditions you must comply with

You must:

  • get the Environment Agency’s agreement before you use this RPS by contacting your regulatory officer or enquiries@environment-agency.gov.uk with ‘RPS 353’ in the subject

  • confirm that you are not able to monitor emissions from the MCP safely or where there is no monitoring port

  • identify when safe and permanent monitoring ports and access will be installed, in line with any planned maintenance scheduled for the generator

  • maintain the medium combustion plant in line with the original equipment manufacturer’s instructions (or better)

  • keep records for 2 years from the date of the last use of the RPS to show that you have complied with this RPS and make these records available to the Environment Agency on request

You must not:

  • use this RPS to avoid monitoring emissions from back-up generators that have a safe and permanent means of access for monitoring

  • use this RPS to install new back-up generators without suitable monitoring access

4. When you must check back

The Environment Agency intends to review this RPS by 9 July 2028.

The Environment Agency can withdraw or amend this regulatory position before the review date if they consider it necessary. This includes where the activity and circumstances that this RPS relates to have not changed.

You will need to check back from time to time, at and before the review date, to see if this RPS still applies.

You can subscribe to email updates about this RPS. These will tell you if the RPS has changed and when it has been withdrawn.

This RPS remains in force until it is removed from GOV.UK or is otherwise identified as having been withdrawn.

5. If you cannot comply with this RPS

If you operate under this RPS but can no longer comply with it, you must:

6. Contact the Environment Agency

If you have any questions about this RPS, email enquiries@environment-agency.gov.uk with ‘RPS 353’ in the subject.

Back to top